Cement finishing float blade



June 12, 1951 w. J. ROOT 2,556,983

- CEMENT FINISHING FLOAT BLADE Filed May 5, 1949 INVENTOR.

Mime J/Foar BY w ffim Patented June 12, 195 1 ()ElVIEN T FINISHING FLOATBLADE Walter J. Root, Monterey Park, Calif.

Application May 5, 1949, Serial No. 91,523

2 Claims.

This invention relates to demountable float blades for attachment to thefinishing blades of a cement finishing machine.

The main objects of this invention are: to provide an improved floatblade which is readily demountable on the finishing blades of a standardrotary cement surface finishing machine; to provide a demountable floatblade which has a plurality of points of contact or support on thefinishing blade; to provide a demountableor detachable float blade whichmay be quickly and readily attached to or demounted from the finishingblade of a rotary cement finishing machine of standard construction; toprovide a float blade of this character of simple and economical design,but of extremely rigid construction which will maintain its shape whensubjected to long and hard wear; to provide a demountable float blade ofthis character which is reversible in application so that when oneportion thereof becomes worn through use, it may be reversed and therebysecure longer use before completely wearing out; and to provide a floatblade of this character which is supported at a plurality of spacedpoints so as to maintain its finishing surface in a straight plane whensubjected to hard usage.

An illustrative embodiment of this invention is shown in theaccompanying drawings, in which:

Fig. 1 is a view in perspective of a gasoline motor driven rotary cementsurface finishing machine having my improved float blade attached inposition on the finishing blades of such machine;

Fig. 2 is a top plan view of the improved float blade;

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2 looking inthe direction indicated by the arrows, and showing the machinesfinishing blade and its supporting arm in broken lines;

Fig. 4 is a transverse sectional view taken on the line 44 of Fig. 2looking in the direction indicated by the arrows and showing themachines finishing blade in broken lines; and

Fig. 5 is an enlarged fragmentary transverse sectional view showing themeans for demountably attaching the float blade to the finishing bladeof a rotary cement surface finishing machine, the finishing blade beingshown in broken lines.

In the finishing of cement or concrete surfaces, it is desirable tofirst work the surface of the newly poured cement or concrete with afloat blade, particularly where coloring pigment or the like is spreador scattered over the surface of the cement. The float blade will tendto work the color into the surface and at the same time bring up thefine aggregates or components of the surface so as to give a smoothuniform surface when finally finished and dried.

The customary practice is to first work the newly poured surface withfloat blades on a rotary power driven finishing machine, andthereafterfinish the surface with the float blades removed, andutilizing the finishing blades with which such standard rotary machinesare ordinarily equipped.

The float blade of the present invention has superior characteristicsover those now in use, particularly in two respects. First, the blademay be quickly and readily attached to the finishing blade of a standardrotary surface finishing machine, and may be attached in either of two.positions-that is, reversed front-to-rear or end-to-end, therebysecuring longer wear from the blade before it is completely worn out,and second, the blade of the present invention is supported on thefinishing blade with a plurality of points or areas of contact so thatthe float'blade contains a plane surface to give a smooth and evenfinish to the cement surface being worked upon.

In the construction shown in the drawings, a gasoline motor drivenrotary finishing machine, generally designated 6, is provided with thecustomary rotary power driven head 8 which carries three radiallydisposed equi-angularly spaced arms In, I2, and [4, on which are mountedthe surface finishing blades l6, l8, and 20, respectively.

My improved float blade comprises a substantially rectangular elongatedsteel plate 22 having an upturned marginal edge 24 around all edgesthereof. That is to say, the side edges and end edges are turnedupwardly from the plane of the float blade an equal and uniform amountso as to ride over the surface of freshly poured cement or concrete, addrigidity to the blade or plate, and provide points of support for theplate when attached to one of the finishing blades l6, [8, or 20.

The top surface of the float blade 22 is provided with spaced parallelstraps 26, 28, and 30 spot welded or otherwise rigidly secured thereto,and which have a thickness equal to the amount of the upturned marginaledge 24 so that the top surfaces of the straps 26, 28, and 30 and thetop edge of the upturned margins 24 all lie in the same plane.

The opposite ends of the straps 26 and 30 have both ends reversely bentin spaced parallel relation, as shown at 32 in Fig. 5, and are providedwith threaded holes therethrough for receiving set screws 34. It isdesirable and preferable that the reversely bent ends 32 are formed witha square sharp shoulder as shown at 36 so that the finishing blade towhich they are attached will fit snugly into the corner and provideabearing for the finishing blade to contact when driven in use. The spacebetween the reversely bent ends 32 of each strap is greater than thewidth of the finishing blade upon which it is mounted, so that it may beassembled thereon readily by sliding on with an endwise movement.

As shown most clearly in Fig. 4 of the drawings, one of the reverselybent ends of each of the straps only need be provided with a set screw,and the opening in the other reversely bent end of each strap is merelyfilled with a short threaded screw to keep the threads clean when usedin soft cement or concrete and the like.

In the use of this fioat blade, the same ends 32 of the two straps areplugged with short screws to keep the threads clean, and the other ends32 are provided with set screws 35 backed away so as to give plenty ofroom for slipping the float blade endwise onto the finishing blade of arotary cement finishing machine. The finishing blade upon which thefloat blade is mounted is then snugly fitted into the sharp corners .36of the reversely bent portions 32, and the set screws 34 tightened downas shown in Fig. 5 of the drawings.

It is to be noted that when in mounted position, the finishing blademakes contact at each of the upturned ends or marginal edges 24 of thefloat blade, as Well as lying on the top surfaces of the cross straps26, .28, and 30, thus giving five points of contact or support for thefloat blade on its finishing blade, as shown most clearly in Fig. 3 ofthe drawings,

Although but one specific embodiment of this invention has been hereinshown and described,

it will be understood that numerous details of the construction shownmay be altered or omitted without departing from the spirit of thisinvention as defined by the following claims.

I claim:

1. A float blade for a concrete finishing machine comprising: anelongated substantially rectangular plate having a plane surface, withthe margins thereof curved upwardly; a plurality of straps mounted onthe top surface of said plate, the top surfaces of said straps and thetop edges of said upturned margins lying in the same plane so as toprovide a plurality of seats for uniformly contacting a finishing bladewhen secured thereon, the ends of said straps being :reversely bent inspaced parallel relation toreceive the finishing blade of a cementfinishing machine; and set screws threaded through said reversely bentends to engage such finishing blade.

2. A float blade for a concrete finishing machine comprising: anelongated substantially rectangular plate having a plane surface, withthe margins thereof curved upwardly; a plurality of straps mounted onthe top surface of said plate, the top surfaces of said straps and thetop edges of said upturned margins lying in the same plane so as toprovide a plurality of seats for uniformly contacting a finishing bladewhen secured thereon, both ends of each of said straps being reverselybent in spaced parallel relation to embrace the finishing blade of acement finishing machine; and set screws threaded through said reverselybent ends to engage such finishing blade.

WALTERJ. ROOT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,082,802 Full Dec. 30, 19132,101,895 Boulton Dec. 14, 1937 2,108,470 Boulton 2. Feb. 15, 19382,300,746 Phillips Nov. 3, 1942

